Parallel running of dynamo-machines.



No. 848,489. PATENTED FEB 5, 1907. C. A. PARSONS & G. G. STONEY.

PARALLEL RUNNING OF DYNAMO MACHINES.

APPLICATION FILED JULY 25, 1905.

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No. 848,489. PATENTED FEB. 5, 1907. O. A. PARSON$ & G. G. STONLY.PARALLEL RUNNING OF DYNAMO MACHINES.

APPLICATION FILED JULY 25,1905.

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PATENTED FEB. 5, 1907. G. A. PARSONS & G. G. STONEY. PARALLEL RUNNING 0FDYNAMO MACHINES.

APPLICATION FILED JULY 25,1905

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- flra/W No. 843,489. PATENTED FEB. 5, 1907. 0. A. PARSONS & G. G.STONEY. PARALLEL RUNNING 0F DYNAMO MACHINES.

APPLICATION FILED JULY 25, 1905.

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CHARLES ALGERNOX PARSONS AND GEORGE GERALD STONEY, OF

.NEWCASTLE-L'PON-TYN E, EN GLAND TO SAID PARSONS.

; SAID STONEY ASSIGNOR- PARALLEL RUNNING OF DYNAIVlO-IVIACHINES.

Specification of Letters Patent.

Patented Feb. 5, 1907.

' Application filed July 25, 1905. Serial No. 271,248.

Be it known that we, CHARLES ALGnnNon PARSONS anl GEORGE GERALD STONEY,subjccts of theKingol' Great Britain and Ireland and residing at lleatonWorks, Newcastleupon'ly11e,ln the county ol Nort hum berland, England,have invented certain new and useful improvements Relating to theParallel Running of Dynamo.\lachines, of which the following is aspecification.

()ur invention relates to the parallel run ning of continuous-currentlynamo-machines which are compensated for armature reaction. In suchmachines We have found in certain instances dilllculty in running inparallel with other dynamos when the limbs of the magl'iets have hadcompounding coils iitted. it is also possible that such dilliculty mightarise in the case of plain shunt-wound machines titted with ourcompensating coils. \Ve are aware that equalizing-wires have been usedin the case of the compound windings on dynamos to obtain stability ofload when two or more machines are run in parallel; but we have foundthat such an arrangement is not sui'licient in some cases to obtainstability when using our compensating winding.

The object of this. invention is to enable dynamos which are compensatedfor armature reaction to run in parallel, automatically dividing theload between them.

The invention consists in cross-connecting part of the compensatingcoils as well as part or the whole of the compounding coils by anequalizing wire or wires, so as to obtain stability of running under allconditions.

Referring to the accompanying diagrammatic drawings, Figure 1 shows onemethod of applying our invention. Fig. 2 shows another modification.Fig. 3 shows a variation of the arrangement shown in Fig. 2. Fig. 4illustrates a modification in which a combined compensating and reversecomnoundii'lg coil is used. Fig. 5 shows the applicatiorrof theinvention to machines having a Deri serics compensating winding, whileFig. 6

shows our invention appliczl to machines having a series compensatingcoil which at the same time gives compounding or overco1npoundin Fig. 7diagrannnat t-ally illustrates the connections of the compensating coilaccording to one form.

In the arrangements illustrated two dynamos are arranged in parallel, (1(I bring the armatures and Z) Z) the shunt field-coils. In themodification shown in Fig. 1 we cross connect by an equalizingavire (aat points intcrmediate between the brushes 0 c of the dynamos and thepoints f f, where the compensating windings (Z (Z are connected to thecompounding coils g g. The compensating windings consist ofcurrent-carrying conductors connected in series with the armature, fixedaround, but not attached to, the armature periphery-for example, byembedding them in the polar faces and carrying them be tween the poleson suitable non-magnetic segments. This is diagraml'i'iaticallyrepresented in Fig. 7 ,wherein the coil 1, shown thus for clearnessarranged around the armature space and partly carried by nonmagneticscgments 2, is connected in series with the ordinary compound winding 3.The polar plane of the compensating winding preferably coincides withthe plane of commutation at no load, yet in some cases it is preferredto place it at an an gle thereto by suitably disposing the winding in.order to secure in some classes of machine a minimum of sparking at allintermediate loads to full or over load. For example, in Fig. 7, whichmay for this case be considered as an eX- planation of Fig. 4, the planeof commutation at no load is represented by the line UVVV and the planeof the compensating winding by XVY, the angle between them being UVX. Itwill be seen that the effect of this method of connection is that withvarying load part of the compensating coils have a constant excitationequal to the mean output of the machines coupled in parallelthat is tosay, suppose, for example, a heavier current were lowing in the lowercoil (Z between 0 and 0 than in the upper coil (Z be tween 0 and c thencurrent would flow through c in an upward direction, according tothediagram, the eilcct being that the current in the parts of both thelower and upper coils between 6 andwould be equal and of a value equalto the mean output of the machines, as stated. Thus the equalizing wireor wires are so placed that the whole of the compounding coils andparts-namely, cfof the compensating coils pass the mean current, whilethe other parts namely, 6, eof the compensating coils pass the currentdelivered by the individual machine.

In the arrangement shown in Fig. 2 we lit reverse turns of compoundingcoils 7t It between the compensating coils (I (Z and the forwardcompoui'iding ccils g g and connect the equalizing-wire c at or near thepoint where the reverse turns of the compounding 72/ it are joined tothe ordinary compounding coils. The action and use of the reversewindings is explained clearly with rclbrence to Fig. 2. It is well knownthat for two compoundwound machines to run in parallel they must bedesigned to give a drooping characteristic as the load incrtaises, orelse should one take more than its share of load or tend to drive theother as a motor the ordinary compounding turns would continuallyii'icreasc the effect until the machine was cut or burned out. Reversecompounding turns it are therefore connected, as shown, between the wire6 and the machines in order to obtain, as is quite obvious will beobtained, a drooping characteristic, for the reason explained above. Inorder, however, that the excitation of the machine as a whole shall risewith the load, as with an ordinary compoundnvound machine, forwardcompounding turns 9 are inserted at a point beyond the equalizing connection, whereby they do not tend to destroy the satisfactory parallelrunning of the machines, but yet givethe rising characteristic for themachine as a whole. It is thus seen that the number of forwardcompounding turns may be either equal or unequal to the number ol"reverse, as required.

In Fig. 3 rever e turns of compounding 7t 72- are placed between thecompensating coils (Z (Z, and the brushes (1 c and-the equalizingwire aare attached at the pointsff, where the compensating coils d d join theforward compounding coils g g.

In the modification illustrated in Fig. 4 we combine the con'ipensatingcoil and the reverse compounding coil in each machine in one equivalentcoil 7c, which is similar to the ordinary compensating coil, but thepolar axis of which is inclined to the ordinary position of such axis,as stated above, in a reverse direction to the din ction of rotation, asstated above, and we attach the equalizing-wire at the points ff, asshown in the figure.

\Ve may also apply our invention, as above described, to any otherarrangements for compensating armature reaction, such as the Dori, inwhich a winding in series with the armature is used with or withoutconmmtating-poles, and parallel running of such machines will be therebyimproved. Fig. 5 shows such an arrangement as applied to a machineprovided with a distributed shunt- 3 winding 1) and a series winding (1,the positions lor the equalizing wire or wires being shown at e, andsimilarly in such machines by dividing up the series winding into two ormore parts the ar 'angements shown in Figs. 1 to 4 may be applied.

In many machines in which a series compensaiing coil is used said coilhas been so llllCtl. as at the same time L0 give compounding orovercompounding, as desired. '0 have tound that by placing an equalizingwire or wires (2 (M an iniermediate point between ihe main ierminal ofrho series winding d and the brushes c, as shown in Fig. (5, parallelrunning is improved. We have also found that parallel running isimproved by dividing said winding iii-.o iwo parts, one ol' whichcompcnsaes tor armature reaciion only, while the other gives the desiredcompounding. Al.erna;ivcly reverse compound ing turns may be hired, orkllUCOlllPGllSZLllllg winding may be so placed as to .increascthc dropof voltage between hill and no load, the equalizing wire or wires in allthese cases being arranged in a similar way to that above described.

We do not *ish to be understood as limiting our invention to theparticular forms herein shown and described, as we have merelyillustrated and described convenient forms of the invention, which maybe varied widely with the range of electrical skill wills out departingfrom the spirit of the invention. For example, instead in one form of anequalizing-wire connecting the junction of torward and reversecompounding turns it may connect points in the compensating windings, orinstead of an equalizing-wire connecting the junctions of compensatingand compounding turns it may connect points in the com pensaiingwindings.

Having thus described our invention, what we claim as new, and desire tosecure by Letters Patent, is

1. In combination, a plurality of continuous-current dynamo-macllineshaving series coils compensating for armature reaction; and anequalizingavire cross-connecting certain points within the compensatingwindings of the two machines, as and for the purpose described.

2. In combination; a plurality of continuous-current dynamo-marllineshaving series coils compensating for armature reaction; compoundingcoils on said dynamo ma chines; and an equalizing-wire cross-connectingcertain points within [lie compensaiin'; windings of the two machines aswell asthe compounding coils; as and [or the purpose described.

53. In bombinaiion; a plurality of continuous-current dynamo-marllineshaving series coils compensa'i ing tor armat ure react ion andcompounding the machine. said coils being divided llitt) two parts oneol' which compensates lor armature rea :iion, while the other gives theeonipounding, and. an equalizingwiro cross-connecting certain pointswithin the ci'impensaiing windings ol' the two machines, as and for thepurpose described.

4. In coinbinazion, a plurality of continu- ICO ens-currerd dynaino-meehines having series coils eonlpenszn ing for armature reeerionand eoniponndin rhe machine said coils being divided im 0 1W0 pin-is,one of which compenszries l'or urnnnure rezieiion, while the oiher givesthe eoinpeuinling, reverse eomponndin; inrns; and an equalizing-wireeross-eonnearing (err inn ponns \Vlllllll the eonipensniring' windingsof 'ihe 1W0 machines, as and for ihe purpose described.

5. ln (fUlllhllllhlOll; a plurzrliiy ol eoniinuens-current(lyinnno-imrehines having series eoils eoinpenszn ing for :Lrnniinrel'OllCLlOll and compounding ihe nniehine, szrid coils being divided i1110 two aris, one of which compensates for {LIIIHUUI'O reaction, while theother gives the roniponnding, reverse compound ing iurns incorporznedwiih szrid compenseh in coils, and :in equalizing-wire erossmonnewlineverinin poiins \\i1l1in the compensating windings of ihe 1W0 machines,as and [or rlie purpose. described.

In resiiniony whereol we have signed our names 1o ihis speeilieuiion inthe presence of two subscribing nilnesses.

lllllllillh' Alillllllxllx PARSONS. (llllllillll lilllli-llill STUNEY.Witnesses: i i

HENRY Gnixniui DAKYNS, J12, FREDERICK GORDON .lIAY BEDl-ORD.

